Cardiovascular autonomic dysfunction in uremia.

Cardiovascular morbidity and mortality is common in chronic renal failure patients, and may be explained in part by abnormalities in cardiovascular autonomic regulation. This review discusses the results of cardiovascular autonomic function studies in chronic renal failure patients. While covering most methods of assessing autonomic function, we focus particularly on power spectral analysis methods. These newer techniques are non-invasive, reproducible, and allow the rapid assessment of the integrity of cardiovascular autonomic reflexes at the bedside. The abnormalities of parasympathetic, sympathetic and cardiac baroreceptor function seen in dialysis-dependent patients are highlighted, and their significance in intra-dialytic hypotension and cardiovascular mortality as well as the effects of dialysis and transplantation on these parameters examined. Importantly, studies of cardiovascular autonomic dysfunction in pre-dialysis chronic renal failure patients, when abnormalities may be amenable to intervention to prevent progression and premature cardiovascular morbidity and mortality, are reviewed.